I have a price field in my form i should allow decimal or floating point numbers only , not characters and any other special and white spaces in my price field.

How could i get that?

This is my code :

    $("#foo").blur(function() {
    var price = $("#foo").value;
    var validatePrice = function(price) {
   return /^(\d*([.,](?=\d{3}))?\d+)+((?!\2)[.,]\d\d)?$/.test(price);
}
    alert(validatePrice(price)); // False
});

Fiddle

I have a price field in my form i should allow decimal or floating point numbers only , not characters and any other special and white spaces in my price field.

How could i get that?

This is my code :

    $("#foo").blur(function() {
    var price = $("#foo").value;
    var validatePrice = function(price) {
   return /^(\d*([.,](?=\d{3}))?\d+)+((?!\2)[.,]\d\d)?$/.test(price);
}
    alert(validatePrice(price)); // False
});

Fiddle

• javascript
• jquery

• stackoverflow./questions/15958808/… – Zero Fiber Commented Feb 1, 2014 at 6:07
• No need for Regex if you are using HTML5: jsfiddle/DerekL/6djkS – Derek 朕會功夫 Commented Feb 1, 2014 at 6:12

3 Answers 3

First off, here's the corrected code:

$("#foo").blur(function() {
    var price = $("#foo").val();
    var validatePrice = function(price) {
      return /^(?:\d+|\d{1,3}(?:,\d{3})+)(?:\.\d+)?$/.test(price);
    }
    alert(validatePrice(price)); // False
});

You will need to test for empty values (undefined) separately. Also, if you want to allow negative values use:

/^-?(?:\d+|\d{1,3}(?:,\d{3})+)(?:\.\d+)?$/.test(price);

This regular expression was lifted from the JQuery Validate plug-in by Jörn Zaefferer. I remend you consider using that plug-in as it contains a lot of other features.

In HTML5 it supports checking validity natively if the browser supports it:

$("#foo").blur(function(){
    alert(this.checkValidity());
});

Demo: http://jsfiddle/DerekL/6djkS/

You can always fall back to the good old ugly Regex if the browser does not support it.

Basing on the Number definition used in JSON:

_{(source: json)}

(with the negative, scientific notation parts removed.)

var regex = /^\d*(.\d{2})?$/;
regex.test(price);   //Boolean

For https://stackoverflow./a/21494842/1885344, the correct regex would be

var regex = /^\d*(\.\d{2})?$/;
regex.test(price);   //Boolean

As it is now, it would permits all character as the decimal separator where as it should be only dot (.) character.